UDN2559EB Allegro Microsystems Inc, UDN2559EB Datasheet - Page 7

• Manufacturer Part Number: UDN2559EB
• Description: IC DRIVER QUAD PROTECTED 28PLCC
• Manufacturer: Allegro Microsystems Inc
• Type: Low Sider

Specifications of UDN2559EB

• Input Type: Logic, AND
• Number Of Outputs: 4
• Current - Output / Channel: 700mA
• Current - Peak Output: 1A
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-LCC (J-Lead)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• On-state Resistance: -

2559
TYPICAL OUTPUT BEHAVIOR
CHARACTERISTIC
TYPICAL OUTPUT
INCANDESCENT LAMP DRIVER
lamp reliability and destroy semiconductor lamp drivers. Warming or current-
limiting resistors protect both driver and lamp but use signifi cant power either
when the lamp is OFF or when the lamp is ON, respectively. Lamps with
steady-state current ratings up to 700 mA can be driven by these devices with-
out the need for warming (parallel) or current-limiting (series) resistors.
at minimum resistance and would normally allow a 10x to 12x in-rush cur-
rent. With these drivers, during turn-ON, the high in-rush current is sensed by
the internal low-value sense resistor. Drive current to the output stage is then
diverted by the shunting transistor, and the load current is momentarily limited
to approximately 1.0 A. During this short transition period, the output cur-
rent is reduced to a value dependent on supply voltage and fi lament resistance.
During lamp warmup, the fi lament resistance increases to its maximum value,
the output stage goes into saturation and applies maximum rated voltage to the
lamp.
INDUCTIVE LOAD DRIVER
rectly. The internal fl yback diodes prevent damage to the output transistors by
suppressing the high-voltage spikes that occur when turning OFF an inductive
load.
will raise the fl yback voltage and inprove performance. However, the peak
voltage must not exceed the specifi ed minimum sustaining voltage (V
V
FAULT CONDITIONS
described above, the drive current to the affected output stage is reduced, caus-
ing the output stage to go linear, limiting the peak output current to approxi-
mately 1 A. As the power dissipation of that output stage increases, a thermal
gradient sensing circuit will become operational, further decreasing the drive
current to the affected output stage and reducing the output current to a value
dependent on supply voltage and load resistance.
to reach approximately 165°C will result in an additional reduction in output
current to maintain a safe level.
saturated condition.
Z
+ V
High incandescent lamp turn-ON/in-rush currents can contribute to poor
When an incandescent lamp is initially turned ON, the cold fi lament is
Bifi lar (unipolar) stepper motors, relays, or solenoids can be driven di-
For rapid current decay (fast turn-OFF speeds), the use of Zener diodes
In the event of a shorted load, the load current will attempt to increase. As
Continuous or multiple overload conditions causing the chip temperature
If the fault condition is corrected, the output stage will return to its normal
F
CIRCUIT DESCRIPTION AND APPLICATION
V
OUT(SUS)
).
Protected Quad Power Driver
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
SUPPLY
+
6